1. Field of the Invention
The invention relates to an apparatus for processing wastewater, more particularly to an oil extracting apparatus for removing oil from a water body.
2. Description of the Related Art
As shown in FIG. 1, a conventional oil extracting apparatus 10 includes a drive shaft 11 and a flexible steel belt 12 having a portion immersed in a water body 100. When the steel belt 12 is driven by the drive shaft 11 to turn, oil in the water body 100 will be separated from the water body 100 and adhere to the steel belt 12. The conventional oil extracting apparatus 10 further includes a plurality of oil scraping plates 13 for scraping the oil that adhered to the steel belt 12. After being scraped from the steel belt 12, the oil will be collected for subsequent processing. However, the conventional oil extracting apparatus 10 is only suitable for extracting oil from a relatively deep water body, thereby limiting practical applications of the same.
As shown in FIGS. 2 and 3, another conventional oil extracting apparatus 20 includes a drive shaft 21 and a round plate 22 having a portion immersed in another water body 200. When the round plate 22 is driven by the drive shaft 21 to rotate, oil in the water body 200 will be separated from the water body 200 and will adhere to the round plate 22. The conventional oil extracting apparatus 20 further includes an oil collector 23 and a plurality of oil scraping plates 231 for scraping the oil that adhered to the round plate 22. After being scraped from the round plate 22, the oil will be collected in the oil collector 23. However, since the oil scraping plates 231 apply lateral thrust forces to the round plate 22 while scraping the oil from the round plate 22, moments and torques about the drive shaft 21 are relatively large. The lateral thrust forces may result in damage to the drive shaft 21 after long-term use, thereby increasing the cost of maintenance. In addition, since the drive shaft 21 is located at the center of the round plate 22, the round plate 22 can only be immersed in a water body 200 where the distance between the water level and the drive shaft 21 is shorter than the radius of the round plate 22. When the distance between a water level and the drive shaft 21 is longer than the radius of the round plate 22, the round plate 22 has to be made larger, thereby resulting in a higher moment and torque of force, and in higher manufacturing and maintenance costs.